Ecotoxicological and microbiological characterization of treated wastewater of the city of Virovitica

Analiza pročišćenih otpadnih voda koje se ispuštaju u vodene prijemnike uglavnom podrazumijeva tek utvrĎivanje koncentracije organskih tvari (kemijske i biološke potrošnje kisika) i nutrijenata (dušika i fosfora). Stoga je u ovom radu ispitan i učinak efluenta na bioindikatorske organizme (ribe (Carassius gibelio)) i gujavice (Eisenia fetida, Oligochaeta)) i stupanj rezistentnosti bakterijskih izolata na antimikrobne lijekove podrijetlom iz otpadnih voda, s ciljem utvrĎivanja štetnog djelovanja na ţiva bića u vodi, a posredno i na zdravlje ljudi. U tom smislu provedena su ekotoksikološka ispitivanja na bioindikatorskim modelnim organizmima, izvršeno je mjerenje mehanizma multiksenobiotičke otpornosti i vrijednosti parametara oksidacijskog stresa. Citogenetska oštećenja utvrđivana su mikronukleus testom a mutageni učinci Ames testom. Izvršena je komparativna mikrobiološka analiza standardnim mikrobiološkim testovima i MALDI-TOF spektrometrom masa, te su provedena hematološka i histopatološka istraţivanja. Rezultati navedenih istraţivanja pokazuju da pročišćene otpadne vode unošenjem ksenobiotika mijenjaju okolišne parametre recipijenta, dovode do porasta otpornosti bakterija na antibiotike, histopatoloških promjena i oksidacijskog stresa u riba. Dobiven je cjeloviti prikaz utjecaja pročišćenih otpadnih voda na ključne prarametre kakvoće i ekološkog stanja vode i biote.Currently, analysis of treated wastewater discharged from the wastewater treatment plants (WWTP) inflowing into recipients involves determination of concentrations of organic substances (chemical and biological oxygen demand) and nutrients (nitrogen and phosphorus). In this study, the impact of effluent on organismic bioindicators and degree of resistance of bacterial isolates to antimicrobial drugs originating from wastewater has been evaluated with the aim to determine toxic effects on aquatic (fish, Carassius gibelio) and terrestrial (earthworm, Eisenia fetida, Oligochaeta) organisms, and indirectly on human health. The ecotoxicological testings on bioindicator model organisms were conducted, measuring mechanisms of multixenobiotic resistance and parameters of oxidative stress. Cytogenetic damages were determined by micronucleus test, and mutagenic effects with Ames test. Comparative microbiological analyses were made with conventional methods and mass spectrometry analyser. Results of this study show that treated wastewater (leaving WWTP) changed environmental parameters by introduction of xenobiotics, contributed to microbial contamination and antimicrobial resistance, histopathological tissue changes and oxidative stress of examined organisms. Hencewith, our approach encompassed an integrated overview of the impact of treated wastewater on key environmental and organismal parameters